This invention relates to a construction of fixing a connector through which signals are fed to and from a printed circuit board and through which electric power is supplied to the printed circuit board, and more particularly to a connector fixing construction suited for a junction block in which a printed circuit board is connected integrally to a board having bus bars and connectors, and the printed circuit board and the board are covered with a cover.
Usually, many electronic devices for effecting various controls are mounted on an automobile or the like, and therefore many connectors have been used to connect the electronic devices to wire harnesses and to connect the wire harnesses together. Also, there has been used a junction block in which the electronic devices and the connectors are mounted in a generally concentrated manner to provide a unitary construction.
A connector fixing construction of a conventional junction block (hereinafter referred to merely as "JB") will now be described with reference to FIGS. 9 through 13. As shown in FIGS. 9 and 10, in the JB 41, a printed circuit board (hereinafter referred to merely as "PCB") 42 is fixedly mounted on a board 44 through spacers 43. Connectors 45 and various parts P including resistors, capacitors and shielded coils, are mounted on the PCB 42.
Various parts P are mounted on the board 44, and bus bars 47 and 48 and so on are also mounted on the board 44. Although only part of the bus bar 47 is shown in FIG. 10, ends of the bus bar 47 serve as external connection terminals for a fuse cavity 49 when the JB 41 is assembled. Ends of the bus bar 48 serve as external connection terminals for connectors 51 when the JB 41 is assembled.
When the JB 41 is assembled as shown in FIG. 9, the upper sides of the PCB 42 and the board 44 are entirely covered with a cover 52 of a synthetic resin while the lower sides thereof are covered with a cover 53. A fitting side of each connector 45 is disposed generally flush with an opening formed through an upper wall of the cover 52, and hence is exposed to the exterior through this opening. The fuse cavity 49 and the connectors 51 are projected from the upper surface of the cover 52.
The internal structure of the JB 41 will be described with reference to FIGS. 11 and 12. FIG. 11 is a cross-sectional view taken along the line XI--XI of FIG. 9, and FIG. 12 is an enlarged, cross-sectional view of an important portion of FIG. 11.
As shown in FIG. 11, a bus bar 54, extended through the board 44, is connected at one end to a circuit pattern 46, and the other end of the bus bar 54 is electrically connected to the bus bar 47 and so on through a conductive member 55. As shown in FIG. 12, the circuit pattern 46 is formed on a lower surface of the PCB 42, and terminals of the various parts P and terminals 45a of the connectors 45 are soldered to the circuit pattern 46.
As shown in FIG. 12, the connectors 45, the PCB 42 and the cover 52 are arranged such that the terminals 45a of each connector 45 extend through the PCB 42, and are soldered at their distal ends to the circuit pattern 46. The connector 45 is fixedly secured or fastened at its central portion to the PCB 42 by a screw 56. A large gap G is formed between the peripheral edge of the opening, formed through the cover 52, and the peripheral surface of the connector 45, and the two are normally out of contact with each other.
When connecting the connector 45 to a mating connector (not shown), the mating connector is inserted at its front end into the fitting side of the connector 45, and is pushed downward to be fitted in the connector 45. When removing or withdrawing the mating connector from the connector 45, the mating connector is pulled upwardly to be withdrawn from the connector 45.
However, in order to prevent incomplete contact and so on, terminals of the mating connector are press-connected respectively to the terminals of the connector 45, and therefore a suitable degree of frictional resistance develops therebetween, and therefore the mating connector can not be easily connected to and removed from the connector 45 merely by urging the mating connector downwardly and upwardly, and particularly when removing the mating connector, in some cases, it is forcibly swung to be withdrawn from the connector 45.
More specifically, as shown in FIG. 12, when withdrawing the mating connector from the connector 45, the connector 45 is forcibly swung in directions indicated by arrows B since the large gap G is formed between the connector 45 and the peripheral edge of the opening in the cover 52. As a result, a load is applied to the area of soldering between the terminals 45a and the circuit pattern 46, so that the solder portions may be cracked. If this occurs, the connection between the terminals 45a and the circuit pattern 46 becomes incomplete, so that the proper circuit operation fails to be carried out.
Further, as shown in FIG. 13, when connecting the mating connector to the connector 45 by pushing the former into the latter, the PCB 42 is deformed from a horizontal condition (indicated in phantom) into an arcuate or curved condition indicated in solid lines. When withdrawing the mating connector from the connector 45, the PCB 42 is deformed upwardly from the position (indicated in phantom) into an arcuate condition. As a result, a load is applied to the solder portions when inserting and removing the mating connector, so that the above-mentioned problems have been encountered.